A white bird with an unfeathered black head and neck, and a long, decurved, black bill. The scapular feathers are blue-black and the flight feathers are black-tipped, giving a narrow black edge to the wing. Groups of birds often fly in a 'V' formation. During breeding, the naked skin on the underwings turns scarlet and the flank feathers become yellow.
Sexes are alike but male is longer-billed. Juvenile and immature differ from adult by having off-white feathering on the neck. Juvenile has greyish cast to the feathers.
Ranges from off-shore islands and estuaries to grassland and vleis. Regular at man-made wetlands and croplands.
Their diet consists mainly of invertebrates but they also eat eggs and chicks, carrion and refuse.
A loud craoking given at breeding colonies.